Multi-circuit trip free overload switch



4 SheetsSheet 1 K. A. BRANDENBERG MULTI-CIRCUIT TRIP FREE OVERLOAD SWITCH April 20, 1965 Filed June 9, 1961 INVENTOR. KAQL A. BPANDENBEEG April 20, 1955 K. A. BRANDENBERG 3,179,757

MULTI-CIRCUIT TRIP FREE OVERLOAD SWITCH Filed June 9, 1961 4 Sheets-Sheet 2 Hwy/06 n FE. 7 a m C@ KARL 4. B/QNDENBEG MULTI-CIRCUIT TRIP FREE OVERLOAD SWITCH KARL ,4. BPAA/DEA/BEG April 20, 1965 K. A. BRANDENBERG 3,179,757

MULTI-CIRCUIT TRIP FREE OVERLOAD SWITCH Filed June 9, 1961 4 Sheets-Sheet 4 M511 M512 F75. i3

IN V EN TOR.

KARL A. BPANDENBEQG United States Patent O l 3,179,757 MULTI-CIRCUIT TRIP FREE OVERLOAD Y SWITCH Karl A. Brandenberg, San Leandro, Calif., assignor to Square D Company, Park Ridge, Ill., a corporation of Michigan Filed June 9, 1961, Ser. No. 116,091

14 Claims. (Cl. 200-124) This invention relates to switch mechanisms and is more particularly concerned with a protective switch which will respond to excessive current in any one of a plurality of circuits.

The primary object of the invention is to provide a thermal overloadrelease switch which will embody trip free features, which can be manually reset by a single operator providing the overload conditions in any one of a plurality of circuits have been corrected and a unitary assembly formed of a plurality of segments, each of which has relatively few parts, and can be economically manufactured and assembled. A further object of the present invention is to provide an overload release switch assembly of a plurality of individual segments, one of which contains a plunger operated switch mechanism that is trip free and the remaining sec- ,tions contain fusible thermal current responsive elements of the'solder pot type.

An additional object of the present invention is to provide anoverload release switch assembly of a plurality of individual segments, one of which contains a plunger operated trip free switch mechanism located to form one end of the assembly and the remaining segments each contain fusible thermal current responsive elements of the solder pot type having a ratchet wheel that is located on an axis parallel to the axis of movement of the plunger and wherein one side of each segment is provided with a connector for receiving the bared end of a conductor and the opposite side of each segment is provided with a rigid conductor extending parallel to the base and equally spaced therefrom.

Another object of the present invention is to provide a thermal overload release or protective switch which incorporates a novel trip free plunger operated switch mechanism and a plurality of current responsive elements, each of which is operatively connected with each other and the switch mechanism, so an overload current through any of the elements will cause the contacts of the switch mechanism to open and wherein each of the current responsive elements is actuated when the plunger is depressed for closing said switch contacts after the overload current has ceased to ow through all of said elements.

Further objects and features of the invention will be readily apparent to those skilled in the art from the speci- Ywall of the assembly removed to show one side of the parts forming one of the thermal voverload elements in one position.

FIG. 4 is a cross-sectional view taken along line 4--4 in FIG. 2 with portions of the Vouter left end wall of the assembly removed to show one side of the switch mechfanism in the left end of the switch in FIG. l.

FIG. `5 is a cross-sectional view along line 5-5 in FIG. 2 illustrating the opposite side of the parts in FIG. 3

with the parts in another position.

3,179,757 Patented Apr. 20, 1965 ICC FIG. 6 is a View of the front side of the device in FIG. 1.

FIG. 7 is a cross-sectional view taken along line 7--7 in FIG. 6 with a portion of the left end of the assembly broken away showing the top side of the parts illustrated in FIGS. 3 and 5.

FIG. 8 is a sectional view taken along line 8 8 in FIG. 7.

FIG. 9 is a cross-sectional view taken along line 9*-9 in FIG. 2.

FIG. l0 is a side view of the device as shown in FIG. 1 connected to a magnetically operated circuit opening and closing device, particularly showing the electrical connection between the devices. Y

FIGS. ll, 12 and 13 respectively show the switch parts as in FIG. 4 in the tripped position, the position of the switch parts when the switch plunger is initially and fully depressed, and when the parts are in theY reset position.

FIG. 14 is a View of the opposite side of the parts in FIG. ll with the contacts removed.

FIG. 15 is a view taken along line 15-15 in FIG. 2 in the direction of the indicating arrows with all portions of the covering walls of the lassembly removed.

In the drawings, and in FIGS. l, 2, 6 and 9 particularly, a protective switch is shown wherein the numerals 20, 21, 22 and 23 designate a plurality of individual segments formed of individual molded parts which are nested side by side to form a common housing indicated by the numeral 24. As shown in FIG. 9, the segment 23 is provided with a left end wall 23a. A right end wall 23b for segment 23 is provided by a left end wall for segment Z2. The segments 20 and 21 each have end walls 20u and 21a respectively, which form dividing walls between the segments 20-22. The segment 20 is also provided with an end cover 2Gb. The segment 23, disposed on the left end of the housing 24, contains a plunger operated, trip free switch mechanism which will be hereinafter described. The segments 20, 21 and 22 each contain a fusible current responsive means which are operatively connected with one another and with the switch mechanism in segment 23, as will be hereinafter described.

The shape of the parts of the switch mechanism in segment 23 is most clearly shown in FIGS. 2, 4, 9, 14 and l5. The switch mechanism, enclosed in segment 23 between walls 23a and 23h, includes a vertically movable reset plunger 25. The plunger 25 is guided by walls 23a and 23]; and normally :biased upwardly and outwardly through an opening 26 in the top of segment 23 iby a spring 36 which has one end resting on a projection 28 formed on wall 23b and the other end resting on an end Wall of a recess in the plunger 25. Included within the segment 23 isa contact actuating lever 32 which is movable both rotatably and vertically labout a pivot, formed as oppositely extending lugs on the front and rear end faces of 'lever 32. The lugs 34 which form pivot are received in suitably located vertical elongated slots 37 in opposite side walls 23a and 23b. The switch mechanism also includes a latching lever 38 which is immovable in a linear path but rotatable about a pivot. The pivot is provided by oppositely extending lugs 40 on the front and rear end walls of lever 38 which are also received in circular recesses formed as suitable openings 23C and 23d in walls 23a and 231;, as in FIG. 9. The lugs 34 and 40 which provide the pivots are disposed along a vertical axis which is horizontally spaced from the path of movement of plunger 25. Positioned between levers 32 and 38 is a spring 44 which, as in FIG. 4, normally urges the lever 32 in a counterclockwise direction about its lugs 34 and the lever 38 in a clockwise direction `about its lugs 40. When the plunger 25 is depressed, a portion 46 on the bottom edge of plunger 25, as shown in FIG. l5, engages an extending lug portion 48 Ywhich is formed on a rear end face of lever 32. The downward movement of plunger through portions 46 and 48 moves the lever 32 downwardly in slot 37. The switch mechanism includes a pair of stationary contacts 56a and 56h and a movable contact 52. The stationary contact 50h is connected with a wire connector 54, located as shown in FIG. 6. The stationary contact 50a is connected to a wire connector 53, located external to the housing 24. The contact 52 is carried on the end of a leaf spring 58 which is electrically connected to a connector 56. The latching lever 3S is provided with a latching portion 69 which will hook behind a portion 62 formed on the rear end face of the lever 32. The lever 32 is provided with a portion 65 which is engageable with the side wall of plunger 25.

With the above parts in mind, the operation will be described in connection with FIGS. ll-l3. In FIG. 11, the switch parts are Ashown in the tripped position; in FIG. 12, the switch parts are shown in the position wherein the plunger 25 is initially depressed to its fullest extent; and in FIG. 13, the parts are shown as in the reset position with the plunger 25 no longer depressed. When the parts are in the tripped position, as shown in FIG. 11, the spring 44 urges the lever 32 in a counterclockwise direction to a position in the top portion of the slot 37 and the lever 38 in a clockwise direction. When the levers 32 and 38 are thus positioned, a portion 63 of lever 32 engages a portion of the housing and the portion 65 of the lever 32 engages the side wall of plunger 25. When the parts are thus positioned, the contact 52 is disengaged from contact 50b and is in engagement with contact 50a. Thus if contact 50a is connected to a device in an indicating circuit, not shown, the indicating device will be energized when the switch mechanism is in the tripped position.

When the switch parts are to be reset, `as when the force of a nger is manually used to move the plunger 25 downwardly against the force of spring 36, the portion 46 of the plunger will engage the extending lug portion 48 on the lever 32 and move the lever 32 downwardly so the lugs 34 are positioned in the bottom of slot 37. When the plunger 25 has been moved a sutlicient distance toward the bottom of the switch structure the levers 32 and 38 will be positioned as in FIG. 12. Continued depressing pressure on the plunger will cause the levers 32 and 38 of the switch mechanism to remain in the position shown in FIG. 12, with the latch lever 38 having its portion 60 hooked in engagement with portion 62 of the lever 32 and the portion 65 in engagement with the sidewall of plunger 25. When the depressing pressure on the plunger 25 is removed and the parts of the current responsive devices, which will be hereinafter described, are in the proper position so that reset may be accomplished, the parts of the switch will move to the reset position shown in FIG. 13 of the drawings, wherein the plunger 25 moves upwardly under the force exerted by spring 36. As the plunger 25 moves upwardly, the lever 32 moves upwardly so the lugs 34 are positioned at the midportion of `slot 37. The latch lever 8 remains in the rotative position shown wherein portion 60 thereof hooks behind the portion 62 of lever 32. Thus as the bottom edge 46 of plunger 25 no longer provides a depression force on lug 48 of lever 32 and the portions 60 and 62 are engaged to act as a fulcrum, the spring 44 causes the lever 32 to rotate in a counterclockwise direction as the lugs 34 move to the middle of slot 37. The counterclockwise movement of the lever 32 causes a portion 66 of the lever to engage and move the spring 58 and the contact 52 from its engagement with contact 50a into engagement with contact 50h. When the parts are in this position, the reset operation is complete, -as shown in FIG. 13. In this connection it -is to be noted that even if the plunger 25 is again depressed after the reset operation is completed, the portion 48 of lever 32 is positioned out of the path `of movement of portion 46 of the plunger. Thus the device is trip free, as a maintained initial depressing force on the plunger 25 will prevent rotation of lever 32 to cause the switch contacts 50h and 52 to close and after the initial depressing force on plunger 25 is released so engagement occurs between the contacts 501i and 52, a redepression of the plunger will be without effect. The contact 56h as in conventional practice, may be included in circuit with the actuating coil of a magnetically operated motor starter so the motor starter may be energized only if contacts 5611 and 52 are closed.

The movable parts contained within the segments 25h22 are identical, and hence only the parts shown in segment 22 will be described particularly. Each of the segments contains a current responsive means which includes a solder pot type current responsive unit 70 which has a heater element, not shown, connected in series with a circuit to be monitored. A typical example of a current responsive unit 76 which may be used is disclosed in the Van Valkenburg Patent 1,752,514, issued April 1, 1930. When the current owing through the monitored circuit and therefore heating element of the unit 70 exceeds a predetermined value, the solder within the unit 70 melts, permitting a ratchet wheel, indicated by the numeral 72, to rotate. Normally the solder is in a solid state and surrounds the shaft whereon the ratchet wheel is fixed to hold the ratchet wheel r2 against rotation. The solder pot current responsive unit 76 as shown in the drawings diters from conventional well known solder pot devices, as shown in the Van Valkenburg patent, in that its ratchet wheel 72 is positioned on an axis perpendicular to the heating element and thereby, as shown in the drawings, is perpendicular to the base of the assembly 24 and parallel with the axis of movement of the plunger 25. After the abnormal current tiow through the heating element of the solder pot current responsive unit 7i) ceases, the solder solidifies and thereby prevents rotation of the ratchet wheel 72. The ratchet wheel 7'2 is engageable by a movable ratchet element or lever 7 4 which is pivoted about an axis 76. The ratchet lever 74 which acts as a latching means is normally urged in a counterclockwise direction, as in FIG. 5, and a clockwise direction as in FIG. 3, by a torsion spring which has its convoluted portion 80 centered about the axis 76 and has one end 82 suitably hooked behind a portion of the ratchet lever 74 and its other end 34 resting on a portion 85 of the material which forms a housing of the segments. Also rotatable about the axis 76 is a molded member or part 86 having circular oppositely extending pivot portions 36a and 86b located on the axis '76 and arranged to be received in suitably located recesses inthe material which forms the walls ofthe adjacent housing segments, as in FIG. 9. The ratchet lever 74 has a suitable opening journalled on the portion 86h. The convoluted portion 80 of the torsion spring 78 is arranged to also surround the portion 86b. The molded part 86 has a pair of spaced lugs 88 and 90 formed on a front end face thereof from which pivot portion 86!) extends. The ratchet lever '74 is positioned on pivot portion 86b so as to be adjacent the front end face of part S6 with the lugs 38 and 9@ spaced on opposite sides of the ratchet lever 74, as shown in FIG. 5. The lugs 83 and 90 extend a considerable distance beyond the face of the ratchet lever 74, as shown in FIG. 8. Extending in the opposite direction from lug 90 on the rear end face of the part 36, from which pivot 36a extends, is a single lug 92, located as shown in FIGS. 3 and 9. This lug is arranged to be engaged by the lug 99 of the part 86 in an adjacent segment as shown in FIG. 9. The torsion spring normally urges the ratchet lever 74 into engagement with the lug 38. The lug 38 of the thermally responsive means contained in the segment adjacent the segment wherein the switch mechanism is included, i.e., the lug 88 contained within the segment 22, is arranged to engage a portion 94 which extends from the rear end face of the lever 38 of the switch mechanism contained in segment 23, as shown in FIG. 2.

en any of the current responsive devices 70 in any of the segments 20'-22 is subject to overcurrent conditions causing the ratchet wheel 72 thereof to rotate, if for example, ratchet Wheel in segment 22 is free to rotate, then, the ratchet lever 74 in segment 22 will rotate in a clock wise direction as in FIG. 3, or counterclockwise in FIG. 5. The rotation of ratchet lever 74 through lug 88 will cause part 86 to rotate counterclockwise in FIG. 5 and lug 88 of part 86 in segment 22 will engage portion 94 of the lever 38 and rotate lever 38 counterclockwise as in FIG. 13 to effect the release of the latching engagement between portions 60 and 62. When lever 32 is thus released it moves upwardly in slot 37 under the force of spring 44. The upward movement is limited when the portion 63 engages the housing. Any additional movement of the lever 32 in the slot'37 after portion 63 engages the `housing will cause the lever 32`to rotate, as in FIG. 11, to cause disengagement between contacts 52 and 50b.

When the device is to be reset and the plunger 25 is depressed to its lowest position, as previously described, lever 32 moves vertically downwardly before it rotates. .The lever 32 has an extending lug 49 extending from its ,rear end face, which is located as shown in FIG. 14. The lug 49 engages aV flat surface 90a, shown in FIG. 8, of lug 90 to move part 86 counterclockwise, as in FIG.

.'15, as the plunger is moved toward its fully depressed position. The counterclockwise movement of part 86 will be transmitted through lug 8S to move lever 74 in segment 22'counterclockwise, as in FIG. 15, to a position where it will be latched with the ratchet wheel 72 of the overload mechanism, as in FIG. 5. When the pressure on the plunger is released, the parts will position themselves as shown in the reset position.

When the sections 20-22 are placed side by side it is to be noted that the parts 86 in each of the` segments are movable independently of the ratchet levers 74. If any one of the current responsive units 70 in any of the sections 20-22 is subjected to an extreme current overload, i.e., if the current responsive element in segment 20 is subjected to the overload current so that the ratchet wheel 72 thereof rotates under the force provided by the torsion spring in segment 20, then the ratchet lever 74 associated with the segment 20 will cause the part 86 associated with segment 20'to rotate in a counterclockwise direction, a's in FIG. 5. The lug 90 on the part 86 in segment 20 thus engages the lug 92 of the part 86 in segment 21, to move the part 86 in segment 21 in a'counterclockwise direction. The movement of part 86 in segment 21 is imparted through the lug 90 of the part 85 in segment 21 to lug 92 of the part 86 in segment 22 to move the part 86 in segment 2-2 counterclockwise. This' counterclockwise movement is imparted through lug 9.0 of the part 86 in segment 22 to portion 94 on lever 38-in segment 23 to effect the release of the switch mechanism as has been heretofore described.

The lugs 88 and 90 on the respective parts 86 are spaced l on the opposite edges of the respective ratchet levers 74 so thatthe parts 86 in the respective segments 20-22 may rotate to a limited degree while the ratchet levers 74 are held non-rotatable by the ratchet wheels 72 in the respective segments 20-22. This limited independent rotation between the parts 86 and ratchet levers 74 will permit the overload means in any of the segments 20-22 to respond to overcurrent conditions and trip the switch mechanism in segment 23 independently of the overload means in the other segments. Thus if the ratchet Wheel 72 in any of the segments 20-22 rotates in response to an overcurrent condition, the engagement between the ratchet wheels 72 and ratchet levers 74 of the remaining segments remains undisturbed, even if the parts 86 in the various segments are required to move to accomplish the tripping and resetting of the switch mechanism in segment 23 and the ratchet lever in the segment which has responded to the overlOad conditions.

As shown inFIG. 8, the walls of the segments 20-22 may be provided with suitable outwardly extending surfaces 101 and 102 which will provide a bearing surface to position the ratchet lever 74. The ratchet lever 74 is pressed against the surface 101 and 102 by the convolutions of the torsion spring. vFurther it will be observed from FIGS. 11 and 13 that when the switch mechanism contained within segment 23 is positioned in the reset position the portion whereon the surface 65 is located moves in a counterclockwise direction. If a suitable opening 103, as in FIG. 1, is providedimmediately adjacent the plunger 25, then as shown in FIG. 4, when the device is in the trip position the top surface of lever 38 whereon portion 65 is located will appear in the opening 103 in the cover to visually indicate that the device has been tripped.

Also, as shown in FIGS. 1, 3, 4, 5, and 8, therear side of the device, as in FIG. 1, is provided with rigid male terminals 104 which preferably are horizontally aligned. These male terminals are arranged to be received in suitably located wire receiving terminal connectors, as shown in FIG. 10, of a magnetic switch structure 105, such as a contactor, which on its opposite wall is provided with wire receiving connectors 106. It will be Observed from FIG. 10 that the protective switch 24 is also provided with wire receiving terminals 107 along its front face. The above arrangement will facilitate the connection of the protective switch 24 with the magnetically operated switch 105. Thus when the device is used the line terminals can be connected to the terminals 107 and the leads to a motor, not shown, connected to the terminals 106 so the composite device provides a throughV wiring arrangement. It is also to be noted that the segment 23 is provided with a connector 108 which is arranged to extend through segment 23 from a rigid male terminal 104 to a wire connector 107. This through connector 108, which is frequently used in wiring circuits, not constituting a feature of the present invention, is also included to facilitate wiring of the device. As heretofore stated, material which forms the segments 20-23 andthe end cover 20b, together with the plunger 25, the lever 32, and 38, as well as the parts 86, are of molded material, which may be of thermoplastic or thermosetting types, as well known to those skilled in the art.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What is claimed is:

1. In a protective switch, the combination comprising; a plurality of segments arranged to form a common housing with one of said segments enclosing a plunger operated trip free switch mechanism having a releasable latching member, and the remaining segments each enclosing; a fusible current responsive element, a latching means rotatable about a common axis independently of a similar rotatable latching means which are rotatable about the common axis in a similar adjacent segment from an unlatching into a latching position and from a latching to an unlatching position with the current responsive element, a member rotatable about the common axis having a lug engageable with the latching means in the segment wherein the rotatable member is included for moving the latching means into the latching position with the current responsive element and for being moved by the latching means when the latching means moves to an unlatching position, said rotatable member also having additional spaced lugs having surfaces providing a lost motion connection between the rotatable members in adjacent segments and a connection with the latching member of the switch mechanism for releasing the latching member of the switch mechanism when the current responsive element in any one of the segments responds to an excess current ow.

2. The combination as recited in claim 1 wherein the said one segment is positioned at one end of said housing and the remaining segments are disposed side by side and extend from said one segment to the other end of the housing.

3. The combination as recited in claim 1, wherein the trip free switch mechanism includes; a stationary contact, a movable contact, a depressible plunger, the latching member which is engageable by a lug on the rotatable member in a segment disposed adjacent the one segment and an additional member engageable by the plunger and the latching member for moving the movable contact into engagement with the stationary Contact when the plunger is depressed and the latching means in each ofthe remaining segments are in the latched position with the current responsive elements.

4. The combination as recited in claim 3 wherein the additional member engaged by the plunger and the latching member is spring biased to move to a disengaging position with the plunger when the movable Contact moves to engagement with the stationary contact.

5. The combination as recited in claim l wherein all of the rotatable members in the remaining segments are independently rotatable about the common axis on individual pivots.

6. The combination as recited in claim 5 wherein the rotatable member in a segment common with the latching means provides a pivot for the latching means.

7. The combination as recited in claim 5 wherein the latching means is biased by a torsion spring to the unlatched position and wherein the torsion spring surrounds the pivot ofthe rotatable member.

8. A protective switch comprising; a housing providing a yplurality of spaced compartments, a plunger operated trip free switch mechanism in one of said compartments having a latching member which is movable between a latching and a released position, a fusible current responsive means in each of the remaining segments, each of said current responsive means having; a fusible current responsive element, a latching means rotatable about a common axis independently of a similar rotatable latching means which are rotatable about the common axis in a similar adjacent segment from an unlatching into a latching position and from a latching to an unlatching position with the current responsive element, a member rotatable about the common axis having a lug engageable with the `latching means in the segment Wherevin the member is included for moving Athe latching means into the latching position with the current responsive element and for being moved by the latching means when the latching means moves to an unlatching position, said rotatable member also having additional spaced lugs having surfaces providingfa lost motion connection between the rotatable members in adjacent segments and a connection with the latching member of the switch mechanism for releasing the latching member of the switch mechanism when the current responsive element in any one of the segments responds to an excess current ow.

9. The combination as recited in claim 8 wherein the fusible current responsive means in each 0f the segments includes a ratchet wheel having its axis of rotation parallel with the axis of the switch mechanism plunger.

10. The combination as recited in claim 8 wherein the said one compartment is positioned at one end of said housing and the remaining compartments are disposed side by side and extend from said one compartment to the other end of the housing.

1l. The combination as recited in claim 8 wherein the compartment containing the trip free switch mechanism includes, a stationary contact, a movable contact engageable with the stationary contact, a depressible plunger, the latching member having a latching portion and a portion engageable by one of the additional lugs on the rotatable member of the current responsive means located in a segment disposed adjacent the segment containing the switch mechanism, a contact actuating member engageable by the plunger and with the latching portion of the latching member and a spring positioned between the contact actuating member and latching member for moving the contact actuating member to a position wherein the movable contact engages the stationary contact and the contact actuating member is disengageable from the plunger when the contact actuating member is latched by the latching member.

l2. The combination as recited in claim 11 wherein the member in the compartment common With the latching means provides a pivot for the latching means.

13. The combination as recited in claim 12 wherein the latching means is biased by a torsion spring to the unlatched position and wherein the torsion spring surrounds the pivot of the rotatable member.

14. The combination as recited in claim 8 wherein all of the rotatable members in the remaining compartments are rotatable about the common axis on individual pivots.

References Cited by the Examiner UNlTED STATES PATENTS 1,752,514 4/ 30 Valkenburg 200-124 2,743,326 1/53 Matthias 200-116 2, 824,191 2/5 3 Christensen 200-88 3,096,415 7/63 Walters 200-124 BERNARD A. -GILHEANY, Primary Examiner.

ROBERT K, SCHAEFER, Examiner. 

1. IN A PROTECTIVE SWITCH, THE COMBINATION COMPRISING; A PLURALITY OF SEGMENTS ARRANGED TO FORM A COMMON HOUSING WITH ONE OF SAID SEGMENTS ENCLOSING A PLUNGER OPERATED TRIP FREE SWITCH MECHANISM HAVING A RELEASABLE LATCHING MEMBER, AND THE REMAINING SEGMENTS EACH ENCLOSING; A FUSIBLE CURRENT RESPONSIVE ELEMENT, A LATCHING MEANS ROTATABLE ABOUT A COMMON AXIS INDEPENDENTLY OF A SIMILAR ROTATBLE LATCHING MEANS WHICH ARE ROTATABLE ABOUT THE COMMON AXIS IN A SIMILAR ADJACENT SEGMENT FROM AN UNLATCHING INTO A LATCHING POSITION AND FROM A LATCHING TO AN UNLATCHING POSITION WITH THE CURRENT RESPONSIVE ELEMENT, A MEMBER ROTATABLE ABOUT THE COMMON AXIS HAVING A LUG ENGAGEABLE WITH THE LATCHING MEANS IN THE SEGMENT WHEREIN THE ROTATABLE MEMBER IS INCLUDED FOR MOVING THE LATCHING MEANS INTO THE LATCHING POSITION WITH THE CURRENT RESPONSIVE ELEMENT AND FOR BEING MOVED BY THE LATCHING MEANS WHEN THE LATCHING MEANS MOVES TO AN UNLATCHING POSITION, SAID ROTATABLE MEMBER ALSO HAVING ADDITIONAL SPACED LUGS HAVING SURFACES PROVIDING A LOST MOTION CONNECTION BETWEEN THE ROTATABLE MEMBERS IN ADJACENT SEGMENTS AND A CONNECTION WITH THE LATCHING MEMBER OF THE SWITCH MECHANISM FOR RELEASING THE LATCHING MEMBER OF THE SWITCH MECHANISM WHEN THE CURRENT RERESPONSIVE ELEMENT IN ANY ONE OF THE SEGMENTS RESPONDS TO AN EXCESS CURRENT FLOW. 